Amino acid sources

Calibrations made using certified amino acid sources are of the utmost importance. The evaluation of the content of amino acids in laboratory and field blanks implies a quantitative... 

Fig. 1.3 High-performance liquid chromatography of amino acids. Source Own files... 

These alkaloids can also be derived from non-aminoacid precursors. The N atom is inserted into the molecule at a relatively late stage, for example, in the case of steroidal or terpenoid skeletons. Certainly, the N atom can also be donated by an amino acid source across a transamination reaction, if there is a suitable aldehyde or ketone. Pseudoalkaloids can be acetate and phenylalanine-derived or terpenoid, as well as steroidal alkaloids. Examples of pseudoalkaloids include such compounds as coniine, capsaicin, ephedrine, solanidine, caffeine, theobromine and pinidine (Figure 6). More examples appear in Table 1. 

Semisynthesis Potential for complex molecules containing unnatural amino acids Source availability... 

Amino acids, source of energy during exercise, 48-50 Anaerobic exercise... 

Precipitates can develop in parenteral nutrition admixtures because of a number of factors such as the concentration, pH, and phosphate content of the amino acid solutions, the calcium and phosphorus additives, the order of mixing, or the mixing process. The consequences can be serious. In one cohort study of hospitalized patients who received peripheral parenteral nutrition, a subgroup developed unexplained chest pain, dyspnea, cardiopulmonary arrest, or new interstitial infiltrates on chest radiograph. A change in the amino acid source of a parenteral nutrition mixture was associated with respiratory adverse events that ranged from interstitial infiltrates to sudden death. The events apparently resulted from infusion of calcium phosphate precipitate in an opaque admixture, and the deposition of the crystals in the pulmonary microvasculature (147). 

Phase I and Phase II metabolic reactions require amino acids for enzyme synthesis. A diet that is deficient in amino acid sources (proteins) can result in the individual not synthesizing significant enough enzyme quantities to... 

Albumin also functions as an amino acid source for peripheral tissue. After ingestion and absorption of amino acid-containing foods, albumin transports them to tissue. In addition, pinocytosed albumin itself can serve as a source of amino acids for tissue. The synthesis of albumin by the liver increases after meals, apparently in an attempt to prevent loss or catabolism of essential amino acids. Complexing by albumin appears to be necessary for the transport of some amino acids across membranes, in particular the transport of tryptophan across the blood-brain barrier. 

General chemical formula of amino acids (source IDFL). 

Like all animals, protozoa and helminths have a restricted capacity to synthesize de novo their own amino acids, and essential amino acids must be obtained exogenously from the diet as free amino acids or from proteins by proteolysis. Keto acids, by transamination, can also function as amino acid sources. Parasites, especially protozoa, have a requirement for the majority of the twenty amino acids which are needed for protein synthesis. 

In nonruminant animal and human nutrition, SB (or SBM) often are added to a diet as a protein or amino acid source rather than a carbohydrate source. Soy fiber is an exception to this and may be added to a diet for its specific high fiber concentration, while whole SB hulls may be fed to ruminants as a source of carbohydrates (fiber). 

Figure 14 (a) The peptide bond, (b) the primary structure of a protein, and (c) the commonly occurring i-amino acids. (Source Circular dichroism and linear dichroism, A. Rodger and B. NordSn, 1997, by permission of Oxford University Press.)... 

Amino acid source Acyl chain length Surface tension y (mN m ) cmc r (mM) (10 mol/cm ) Krafft A (area (A )/ point molecule) (°C) ... 

Amino acid source Amino Total Acids per Essential 70 kg B. Wt. Non-Essential... 

First, it was established that expression of the yeast TKLl gene in E. coli led to a functional TK. E. coli auxotrophs expressing the yeast TKLl gene were then used to convert the synthetic compounds 16a and 16b into a usable amino acid source. 

Culture medium MS glucose 0.2% supplemented with phenylalanine, tyrosine, and tryptophan (0.3 mM each), shikimic acid (0.3 niM), pyridoxine (3 pM). and the indicated amino acid source. 

Amino acid Source Value Value Disorder(s)... 

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